1. Field of the Invention
The present invention relates to a lighting apparatus using microwave energy.
2. Description of the Prior Art
A lighting apparatus using microwave energy emits visible rays or ultraviolet rays by applying microwave energy to an electrodeless plasma lamp, it has longer life-span and shows better lighting efficiency than that of an incandescent lamp and a fluorescent lamp.
FIG. 1 is a longitudinal sectional view illustrating a lighting apparatus using microwave energy in accordance with the conventional art.
As depicted in FIG. 1, the conventional lighting apparatus using microwave energy includes a magnetron 2 installed inside a casing and generating microwave energy, a high voltage generator 3 boosting the voltage of utility AC power and supplying it to the magnetron 2, a wave guide 4 connected to an outlet of the magnetron 2 and transmitting microwave energy generated in the magnetron 2, a bulb 5 generating a light by using enclosed luminous materials in a plasma state by receiving the microwave energy transmitted through the wave guide 4, a resonator 6 covering the front portion of the bulb 5 in order to cut off the microwave energy and pass the light emitted from the bulb 5, a reflector 7 receiving the resonator 6 and focus-reflecting the light generated in the bulb 5 straightly, a dielectric mirror 8 installed inside the resonator 6 at the rear of the bulb 5 in order to pass the microwave energy and reflect the light, and a cooling fan assembly 9 placed at the side of the casing 1 and cooling the magnetron 2 and the high voltage generator 3.
The bulb 5 is constructed with a luminous unit 5a made of quartz and ceramic and having enclosed luminous materials in order to emit lights by being excited by microwave energy and an axial unit 5b combined with the luminous unit 5a by welding and extended toward inside the casing 1.
In addition, the bulb 5 cools high heat generated at the luminous unit 5a by being rotated according to a bulb motor 10.
In the meantime, in the conventional lighting apparatus using microwave energy, the magnetron 2 generates microwave energy according to a power apply, the microwave energy generated in the magnetron 2 excites the luminous unit 5a of the bulb 5 after passing the wave guide 4 and the resonator 6, and the luminous unit 5a generates lights. The lights generated in the luminous unit 5a are reflected by the reflector 7, accordingly a lighting function can be performed.
However, in the operation of the conventional lighting apparatus using microwave energy, lots of heat is generated at the magnetron 2, the wave guide 4 and the high voltage generator 3, etc., as depicted in FIG. 1, the magnetron, etc. are cooled by sucking external air into the casing 1 by using the cooling fan assembly 9.
However, because the lighting apparatus can be used at outdoors as well as indoors, in an air cooling type using a cooling fan in order to cool a heat generating unit of the lighting apparatus using microwave energy, impurities such as bugs, dusts, etc. or rain may come into, accordingly the apparatus may be damaged or a life-span of the apparatus may be lowered.
Particularly, if a quantity of a lighting apparatus is increased in order to improve a brightness, heat generated inside the apparatus has to be discharged more efficiently.
In order to solve the above-mentioned problems, it is an object of the present invention to provide a lighting apparatus using microwave energy which is capable of emitting heat generated inside the apparatus to outside more efficiently and having a sealed cooling structure preventable penetration of external impurities.
In order to achieve the above-mentioned object, a lighting apparatus using microwave energy includes a magnetron for generating microwave energy, a bulb for generating lights by the microwave energy, a wave guide for connecting the magnetron and the bulb and transmitting the microwave energy generated in the magnetron to the bulb and a casing housing the magnetron and the wave guide inside and combining with the bulb, herein the casing housing the magnetron is tightly contacted to the exterior of the magnetron in order to emit heat generated in the magnetron.
A lighting apparatus using microwave energy includes a magnetron for generating microwave energy, a bulb for generating lights by the microwave energy, a wave guide for connecting the magnetron and the bulb and transmitting the microwave energy generated in the magnetron to the bulb, and a casing housing the magnetron and the wave guide inside and combining with the bulb, herein the casing and the external surface of the magnetron are formed as one body in order to emit heat generated in the magnetron.